Portable two-directional agricultural heater



y 8, 1952 G. T. NEUNDORFER PORTABLE TWO-DIRECTIONAL AGRICULTURAL HEATER 2 Sl-IEETSSHEET 1 Filed March 14, 1949 6 m a i I 3 D .1 2 7 Z n M fl a 1i A f 3m 6 9i L 7 r a 7 U 1 J INVENTOR. 66am: Z'Meu/vm/vzm I M, f

ATTQRNEYS y 8, 1952 G. 'r. NEUNDORFER 2,602,267

PORTABLE TWO-DIRECTIONAL AGRICULTURAL HEATER Filed March 14, 1949 2 SHEETS-SHEET 2 MFA T0)? 650x05 Z'Mm'wmm I I g ATTOR/VEYS.

temperature, condition of Patented July 8, 1952 UNITED-STATES PATENT OFFICE PORTABLE TWO-DIRECTIONAL AGRICULTURAL HEATER George T. Neundorfer, Chico, Calif. Application March 14, 1949, Serial No. 81,267

5 Claims.

The present invention relates to improvements in a portable agricultural heater. It consists of the combinations, constructions and arrangement of parts, as hereinafter described and claimed.

It is an expensive proposition to maintain smudge pots, or stack-type heaters, for heating orchards to prevent'frost damage to any plant life ordinarily subject thereto. In practically every case, where there is a below-freezing tem perature of approximately 28 Fahrenheit, the product being grown will not become frost bitten, if the atmosphere surrounding the product is raised periodically in temperature about 4 Fahrenheit every half hour. In the interim between heating the prevailing temperature may be permitted to drop again towards 28 Fahrenheit without damage to the product.

Taking into consideration the time element before which frost damage occurs, I propose to provide an agricultural heater that may be moved into an area periodically, depending upon the plant life, moisture content of theair,etc.-

Accordingly, an object of my invention is to provide a portable agricultural" heater adapted to pots, or stack-type heaters. QWhen utilizing such pots and stack-type'heaters, the entire area to be protected must be maintained at'an atmospheric temperature. above freezing. The heating provided by my portable heater carried out periodically at intervalsof time that will prevent frost damage to the crop; w v I From actual tests, I have ioundthat blowing hot air periodically over a given area about every siximinutes 'will raise the atmospheric tempera ture from a below-freezing temperature of 28 Fahrenheit to ajtemperature above freezing so that the growing crop willnot suffer damage.

It is further proposed in this invention to provide a portable agricultural heater, which is compact in construction, durable'andeflicient for the purpose intended. v

More specifically described, I provide an apparatus having a pair of fans facing in opposite directions, and these fans may be tilted about horizontal axis to direct heated air downwardly at a slight angle. This will ,compensate'for' the natural tendency of theheated air to rise. These fans are placed one in front oi the other, when 2 x Y considering the direction of travel taken by the apparatus. One fan directs a heated air stream laterally in one direction, while the other fan directs its heated air stream in the opposite direction. I

Other objects and advantages will appear as the specification continues. The'novelfeatures of my invention will be set forth in the claims hereunto appended. I 1" i I For a better understanding of the invention, reference should be had to the accompanying drawings, forming part of this application, in

which:

Figure l is a top plan view of a portable agriculturalheater constructed in accordance with my invention;

Figure 2 is a side elevation thereof;

Figures 3 and 4 are rear .and'front'elevations, I

respectively, of my apparatus;

Figures 5 and'fi'are vertical transverse sectional views taken alongthe lines VV and -VI.-VI, respectively, of Figure 2; I '1 Figure 7 is a vertical sectional view taken along the line VIIVII of Figure 6 illustrating aburner that may be tilted about a horizontal. axis;

Figure '8 is'aviewlooking at the right-hand side of Figure '7; Q i

Figure'9 "is a horizontal sectional view taken along the line lX-JXof Figure 6; and

Figure 10 is a top plan view of one of the burners as seen from the line X-X of Figure8.

While I have shown only the preferred-form "of my inventiom it should be understood: that various changes, or modifications; may be made within thescope of the annexed claims without departing from the spirit thereof.

In carrying my invention intopractice, I provide a chassisindicated generally at A, which includes a frame I 0 supported on a pair of wheels ll. The forward end of this frame is, adapted to be'coupled to a'towing vehicle B bya draft bar l2, It will be understood, of course, that: the chassis may bedrawn through orchards,-fie1ds and the like, wherein "various crops are grown that'must be protected' against-frost damage.

' While en route through anorchard,'.field,:;or the like, hot air streams are discharged'laterally of the chassis A in opposite directions byi fans designated generally at- C and D. Burners'fC' and D" are as'sociatd'with the'fans C-and D, respectivelmin order to heat air streams flowing through tubular shields I l surrounding the blades 'l5of'these-fans' I 1:;

The fans '0' andD are mounted on opposite sides of the-longitudinalaxis of. the chassis A;ias

clearly shown in Figure 1. These fans are spaced apart, and an engin E, or other suitable prime mover, is interposed therebetween. Likewise, the burners C and D are arranged on opposite sides of the chassis, with the burner C disposed forwardly of the engine E and the burner D mounted rearwardly of the engine. Figure 2 discloses the engine E as being disposed substantially over the wheels H. The arrangement of the fans, burners and engine produce a balanced load on'the chassis A, thus facilitating coupling of the chassis to the towing vehicle B and producing a load that may be towed readily over the ground F.

Referring now to the details of the fans C and D, it will be observed that the tubular shields M are open at their ends, thus permitting air streams to flow therethrough when the fanblades are revolved. The shields carry horizontal trunnions it, which are mounted in clamp-like bearings l1.

Set screws lla retain the trunnions in adjusted position. The latter are carried by standards It rising from the frame In. The shields [4 are adjustable about the axis of the trunnions l6 so as to swing-the axis of the shields (defined by shafts through vertical angles, as suggested in Figure 5. Thus the heated air streams discharged by the fans may be directed downwardly to compensate for the tendency of the hot air to rise. This adjustment has the further advantage of directing theheated air on low-growin plants and shrubs.

These shields have spider-like struts I8 secured thereto. Shafts 20 carry the fan blades [5 and are supported for rotation by the struts [9. Driven pulleys 2| are secured to these shafts, and are operatively connected to a drive pulley 22 on the engine E by belts 23, or other suitable power transmitting means.

The fan C creates an air stream, as suggested bythe arrows a, which passes over a heat outlet 24 of the burner C. The fan D sets up an air stream flowing past a heat outlet 25 of the burner D, as suggested by the arrows b. The heated air streams, suggested by the arrows a and 'b in Figure '1,'are discharged laterally relative to the chassis A in opposite directions.

The heat outlets 24 and 25 are disposed substantially at right angles to the axis of rotations of the fan blades l5, and'are arranged adjacent to the lower peripheral sections ,of the fans. This arrangement not only directs the heat into the air streams, but-the tendency of the heat to rise after it leaves the burners will carry the heat directly into. the air streams being forced through the fans.

Fuel is supplied to the burners C and D by conduits 25 leading from a tank 21. This tank may be carried by the chassis A or by thetowing vehicle B; Butane may be used as the fuel. The conduit 26 for each burner conveys fuel through a regulating valve 28 (see Figure 8) and a pipe 29 conveys this fuel to a fuel-air mixing chamber 30. A branch line 3| leads from the pipe 29 to a conventional pilot 32 for the burner.

The burners C and D are swingable into various angular positions to change the facings of their heat outlets 24 and 25, respectively, with re,- spect to their-respective fans. For this purpose, the main housings 33 ofthe burners are mounted in clamps 34. (See Figures 7 and 8.) In turn, these clamps are anchored to shoes 35. Trunnions 36 project downwardly from the shoes and pass through bearings 31 carried by bars 33.

"Set screws 39 lock-the shoes 35 in adjusted position with respect. to the. bars 38. It will be ap- ,are swingable about the axis of the bolts 40 to depress or raise the heat outlet openings 24 and 25 of the burners relative to the air streams flowing throughthe fan C and D. Set screws 42 are provided for holding the bars 38 in adjusted positions.

. Having thus described the various parts of my portable agricultural heater, the operation thereof is summarized as follows:

When the temperature of the atmosphere be- ..gins to drop toward the point where the crops in a particular area are apt to suffer frost damage, the chassis A is coupled to the towing vehicle B by the draft bar I22 The burners C and D are ignited, and the fans C and D are set in motion by-starting the engine The entire apparatus is drawnthrough the area to be'heated. During this travel, the fans C and D discharge heated air streams, which are forced laterally in the direction of the arrows-a and b, respectively.

In order to compensate for the natural tendency of hot air to rise, the set-screws Ha may be loosened and the fans. adjusted about the axes of trunnions [6 so as to incline the axes c of the fans and thus direct the heated air streamsto- Ward the ground F (see Figure 5) Referring toFigures-l-Z and 7-8, the set-screws 62 may be temporarily loosened and the burners tilted about the-axes of bolts 40. This will swing the axes d 'of the burner heat outlets 24 and 25 with respect to the horizontal. Also, the setscrews 39 may be released in order to allow the axes d of the burner outlets to be swung horizontally toward or away from the tubular shields 14. These two adjustments permit the burners to be swung into various angular facings with respect to the fans C and D, respectively.

During an actual test of -my portable agricultural heater, which is cited byway of an exampleonly, fans of 1-foot diameters were employed, operating at 1000 revolutions-per minute. Each fan displaced between 40,000 and 50,000 cubic feet of air per minute, at a speed of about 45 miles per hour. vThe burners Cand D heated ave 20 Fahrenheit. rise to the air streams in the. vicinity of the burners. The hot air streams were effective for about feet on each side of the chassis A. V V

The'temperature of the, air at the start was 28 Fahrenheit. During the 'firstround through the area, no change in temperature was noted atthe 150 foot distance. The second round gave 1 Fahrenheit rise at 150 feet; the third round added 2 Fahrenheitmore at 1.50 feet; and the fourth round brought the temperature of the air to 32? Fahrenheit, where it was maintained by making a tripthrough the area at 6 minute intervals. It was found that a 10-acre track could be covered every 6. minutes.

In theevent that the temperature is lower than 28 Fahrenheit at the start, more trips will be required to bring the air up to 32 Fahrenheit.

Particular attention is called to the fact-that the fans C and D are'spaced apart along the length of the chassis -A. Part of the .hot air the hot air stream flowing from the fan D will be pulled back by the fan C and heated by the burner vC. Thus advantage is taken of the previous heating of the air.

Ordinary smudge pots utilize an oil that produces a heavy black smoke screen. This is very undesirable, especially when the smudging is done near a metropolitan area. By using butane, no smoke screen is produced.

I claim:

1. In a portable agricultural heater: a chassis movable over the ground; a pair of spaced-apart fans oifset relative to one another along the length of the chassis and mounted on the chassis for rotation, each about a substantially horizontal axis; said axes extending substantially transversely relative to the chassis; one fan being made to produce an air stream flowing laterally from one side of the chassis; the other fan being made to produce an air stream flowing laterally from the other side ofthe chassis; the offsetting of the fans with respect to one another being suflicient so that the air'stream flowing to and from one fan will be unobstructed by the other fan; burners associated with the fans and having outlets for directing their heat into the air streams; a pair of wheels disposed substan-- tially midway between the fans and supporting the chassis; an engine mounted on the chassis substantially above the wheels; thefans, engine and burners producing a load balanced relativeto the wheels; and means operatively connecting the engine to the fans for rotating the latter to move the air streams in the directions aforesaid.

2. In a portable agricultural heater: a chassis movable over the ground; a pair of spaced-apart fans offset relative to one another along the length of the-chassis and mounted on the chassis for rotation, each about a substantially horizontal axis; said axes extending substantially transversely relative to the chassis; one fan being made to produce an air stream flowing laterally from one side of the chassis; the other fan being made to produce an air stream flowing laterally from the other side of the chassis; the ofisetting of the fans with respect to one another being sufficient so that the air stream flowing to and from one fan will be unobstructed by the other fan; burners associated with the fans and having outlets for directing their heat into the air streams; a pair of wheels disposed substantially midway between the fans and supporting the chassis; an engine mounted on the chassis substantially above the .wheels; means operatively connecting the engine to the fans to move the air streams in the directions aforesaid; the fans being mounted on opposite sides of thelongitudinal axis of the chassis, with the connecting means between the engine and the fans extending along this axis; the burner associated with one of the fans being disposed on one side of its fan; and the burner associated with the other fan being disposed onthe opposite side 3. In a portable agricultural heater: a chassis substantially transversely to the chassis; each shield providing a passageway having suction and discharge ends communicating directly withthe atmosphere; a pair of rotatably-supported fans, each being aligned with a passageway of a shield; one fan being made to produce an air stream flowing through the passageway of one shield for discharge laterally from one side of the chassis; the other fan being made to produce an air stream flowing through the passageway of 1 the other shield for discharge laterally from the opposite side of the chassis; means for rotating the fans to move the air streams in the directions aforesaid; these shields being ofiset relative to each other along the length of the chassis so that the confines of one shield is'disposed entirely to the side and beyond the confines oi' the other shield; the suction and discharge ends of each shield being unobstructed by the other shield, whereby the air stream of each shield will be unimpeded by the other shield; and burners having outlets positioned to direct heat into the air streams. I

4. The combination as defined in claim 3, in which the means for rotating the fans includes an engine mounted substantially midway between the shields, with one fan and itsassociated burner disposed on each side of the engine.

5. The combination as defined in claim 3, in which the tubular wind-directing shields are placed sufiiciently close together so that part of the hot air stream being blown laterally from the outlet of each shield will expand into the zone of suction created by the fan of the other shield and will be forced through the latter for further heating, thereby establishing transversecirculation of air having increased temperature over previous heating of the air.

' GEORGE T. NEUNDORFER.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED' STATES PATENTS Number Name 7 Date 641,990 Neyens Jan; 23, 1900 1,793,719 Reader Feb. 24, .1931 1,864,198 Johnson June 21, 1932 1,903,615 Towt Apr. 11, 1933 2,041,969 Seymour May 21, 1936 2,223,597 Brewster Dec. 3, 1940 2,231,454 Saxe Feb. 11, 1941 2,315,096 Sanderson lMar. 30, 1943 g of its fan; the fans, engine and burners producing a load balanced relative tothe wheels. 

